1. Field of the Invention
The present invention relates to a method and apparatus for providing an encrypted key based on a DRM type of a host device, and, more particularly, to a method and apparatus of ensuring compatibility of a host device by providing an encrypted key based on a DRM type of the host device.
2. Description of the Related Art
In general, digital rights management (DRM) is a technique that protects and manages the copyrights of digital content. Content is stored by a content-providing server in encrypted forms and upon a user's purchase request, an encrypted content and key information for decoding the encrypted content are transmitted. DRM specifies a reproducible count, duplicability or count of digital content.
Functions of DRM largely consist of protection of digital content, management of usage regulation, and management of a billing system. DRM technology allows digital content to be protected through an encryption process from generation to distribution/use/disuse of digital content including prevention from illegal distribution or illegal use. In addition, DRM technology allows only a legitimate user who owns an encrypted key to decode and use encrypted content. Even if the digital content is illegally distributed, the digital content cannot be used without the encrypted key, so that it can be protected from illegal use.
FIG. 1 is a diagram illustrating a content playback procedure according to conventional DRM.
Referring to FIG. 1, for the purposes of preventing digital content from being coped and controlling digital content from being distributed, if a predetermined content provider 10 selects a particular solution, e.g., DRM A, and adopts the selected DRM A to generate content, digital content 20 adopting the DRM A can be used on only a device 30 that can be supported by DRM A.
This is because a format of the digital content 20 is converted into a DRM A-dependent one and there is no open service system for providing compatibility between a DRM A system and the device 30 that reads the content of the converted format and attempting to play back the content.
Thus, the DRM-adopting content is dependent on the pertinent DRM technology and the specific solution, and DRM compatibility cannot be ensured between various devices.
Further, there has never been an open system for providing DRM compatibility, which allows content providers, service providers, DRM providers, device manufacturers to freely participate in the DRM system.
Korean Published Patent No. 2005-0091378 discloses a technology entitled “Shift Register and Display Apparatus Comprising the same” in which a plurality of stages are connected to each other and sequentially generate output signals, each stage generating an output signal according to one of a plurality of clock signals having a duty ratio of less than 50% and different phases in response to outputs of two different stages. However, in the disclosed patent, there is no teaching about technology of providing an encrypted key based on a DRM type of a host device.